In analysis of the immune cell subsets using flow cytometry, (1) inhibitory T cells (Foxp3+T cells) and effector regulatory T cells (CD45RA-FoxP3high T cells) tended to increase and (2) granulocyte-macrophage colony-stimulating factor–producing Th cells transiently decreased in both healthy subjects and patients with MS. The gene discussed is CSF2; the disease is myeloid sarcoma.